Apparatus for detecting water and other volatiles



April 14, 1942. I E; G. RAGATZ I 2,280,030

APPARATUS FOR DETECTING WATER AND OTHER VOLATILES Original Fild June 26, 1937 INVENTOR. Edward G. Pagafz BY %4F A TTORNEY.

Patented Apr. 14 1942 t APrAnArUsFon DETECTING H mornr avomrnlns WATER its ..1 r

. Edward Ragatz, San Marino,Calif., assignor to Union Oil Company of California,Los Angeles,

G'aliL, a corporation of California i 1 l Originalapplication are 26., 1931-7, serial No.

150,657. Divided and this application August 22,1938, Serial No. 226,105 f 3 Claims. (01. 196L433) h apparatus... for detecting influxof water, and more particularly pertains, to] a. method and apparatusf whereby,a warning is given whenever excessive quantities of, water or other low boiling A liquids. are presentin 1a relativenhlgher boiling liquid. casels a true division of a; co-

pending. application; Serial No.1 150,657,. filed June 26, 1937; Specifically, the invention is of particular importance in connection with solvent extraction operations, particularly where the solvent employed isiof the type of liquid sulfur dioxide. This is due to theiactthat liquid sulfur dioxide is notcorrosiv'e, while suliurous acid "which. results from. contact of liquid. sulfur dioxide with water is corrosive, particularly when large quantities thereof. are present. Obviously,

althoughthe presence: of small quantities of water in an .oil being solvent extracted are not detrimental dueto'thahigh degree of dilution of the present. invention relates to methods and I In view of the above, "the oils which are treated with solvents; whether for the purpose of separating therefrom the slack wax, or, for example, fortreating a mineral oil distillate to produce fractions'or' components which are, respectively,

- more and less paraifinic in nature than the origsulfurous acid formed,., the inflow or entrance of larger quantities oi: water will tend to form considerable quantities of; sulfur ous acid so that the. concentration thereof in the: oil being. extracted may reach. a point to cause considerable damage to the equipment. 7 i i Also, in the-solvent dewaxing of mineral oil, as is customarily practiced, the oil to [be dewaxed is nixedl with. a solvent, the oil-solvent mix chilled to precipitate wax separated by filtration, centrifuging, .or cold settling from the resultantdewaxed oil; Some of the solvent employed in the process is re- H ained in the separated slack. wax, the bulk of the solvent being normally retained in thedewaxed oil. Forthepurpose of further utilization of thewax, as grwell as to prevent loss, it is desirable to remove this solvent from the slack wax thus produced, Howevendf any water is present in the system,it freezes out and is separated along with the slack wax. i

t In such case, the recovery of solvent from the slack waxgis; accompanied by great di-fliculties. Thus, even iithefsolventused is notof the type ofpvliquid sulfur .dioxide which, ads-aforesaid, reacts With water to produce a corrosive acid, the presence of any appreciable quantities of water is undesirable, particularly when a solvent is employed which miscible orsoluble in water. In

such case, it is extremely difficult to recover the solvent substantially free from water. On the other hand, if the water is not separated from the p system it will gradually accumulate and dilute the solventand this destroys its effectiveness as a dewaxing or solvent extracting agent,

the wax, and the precipitated inal oil treat, areall dehydrated. However, it is impracticaltoremove all traces of water from such oils Furthermore, in large plant operations it frequently occurs that a. certain portion of the oil under-treatment? does not receive the necessarydegree of'jtreatment, with the result that such oil may contain, an unduly large amount of water which, as'stated above, may cause damage tothe trea'tingplant or destroy the effectiveness of the solvent utilized. Itistherefore, the main object of the present invention to eliminate the above disadvantages and to. detect the presence of any appreciable quantities of water in. the oil whichis to undergo treatment with one or more solvents for the purpose or purposes mentioned above.

It is a further object-of this invention to provide a process and apparatus whereby relatively smallnquantities. of water present in an oil to be solvent treated may becontinuously and adequately removed from saidoil prior. to its said solvent treatment, and whereby the presence of any appreciable and/or critical quantities of suchiwater will be immediately detected. so that adequate and proper steps may be taken toprevent any and allot the. above. defects caused by the presence of such water during the solvent extracting or dewaxing operations.

The details of. the. present invention will become apparent from the hereinafter contained description with-particular reference to the an.- nexed drawing, thesingle figure of. which is a diagrammaticview of an apparatus for carrying out a preferred embodiment of the invention.

' .Referringnow more particularly to this drawing,

the oil tobe treated is introduced continuouslythrough line lflinto a tank I 2, line lfl being equipped with a valve I3 which. is actuated by a float ttlocatedyin, tank. [2. so that the level of the oil iii-said tank-is constantly maintained at' I a uniform. and. predetermined level. Line I0 is further provided with a preheater I6, the heating medium .for which enters said heater through line I! and is'withdrawn therefrom through line l8.

The purpose of the heater will be described in detail hereinbelow in connection with the operations of the apparatus or plant. Dome 20 on tank I 2 is provided with a vapor discharge line 2| which leads to a vacuum pump or compressor 22 having only a definite limited capacity. The discharge end of said pump or compressor may be open to the atmosphere or may be connected by line 23 to any other part of the plant. This phase does not constitute any portion of the present invention, and is therefore not shown.

Tank I2 is further provided with a liquid discharge line 25 which may be equipped with a constant volume pump 26 and a valve 21. The tank is also provided with a vent line 29 termimating in a device 30 which consists of an alarm or a similar mechanism which is responsive to and actuable by changes in pressure in tank 12. The operations of the above described system are comparatively simple. Assuming that the stock consists of a lubricating oil which is to be treated with a solvent such as a mixture of liquid sulfur dioxide and benzene for the purpose of resolving said oil into two components which are, respectively more or less parafiinic in nature than the original stock to be treated, this oil,

conveyed into, line Ill from an outside source is first preheated in heater Hi to a temperature of 225 F., and then introduced at said temperature into tank l2, the rate of said inflow being regulated by the float controlled valve l3, and being obviously dependent on the rate of discharge of the oil through line 2-5. In view of the fact that the oil is heated to the above temperature, any water which may be present in the oil will evaporate, and will separate from the oil in tank [2. The pressure in the vapor space above the liquid level in said tank is maintained at a predetermined vacuum by the action of vacuum pump 22, the gases and vapors being withdrawn by said pump through line 2 I. However, because, as stated, this pump is only of a limited capacity, said predetermined vacuum in the vapor space in tank l2 will be obtained only when the oil bein introduced thereinto contains only a very small or substantially negligible percentage of water. If, however, a slug of water enters line In together with the oil to be treated, it will vaporize in heater l6 and will create an excessive pressure in tank I2. In such case, this excessive pressure will be transmitted through line 29 to device 30, thus producing an alarm.

Obviously, many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope of the invention. Thus, although the specific embodiment refers to an assembly used for the detection of relatively excessive quantities of water in an oil fraction to be solvent treated, it is obvious that the same or similar apparatus may be employed to inform the operator when a relatively high boiling point liquid contains an excessive percentage of a relatively lower boiling point liquid. Also, instead of merely producing an audible or visible alarm, the structure may be adapted to operate automatically so that the system may be closed when the above described undesirable condition occurs. For this purpose, it is but necessary to provide conventional relays which will close pumps 22 and 26 (as well as the means introducing the feed into line H!) as soon as the pressure in the upper part of tank l2 has reached a predetermined maximum.

It is also clear that the temperatures and pressures described above may be varied within a wide range. Thus, although the specific example given hereinabove shows that the liquid is preheated to a temperature of about 225 F., it is obvious that this temperature may be lower or higher so long as the Water in the oil is vaporized. Obviously, if the low boiling substance in the liquid has a different boiling point or range from that of water, the degree of heating may be varied accordingly. As to the pressure in the vacuum tank I2, as well as the pressure differential which will actuate alarm 30, these may be regulated at will to obtain the desired results enumerated and described above.

It is therefore to be understood that the invention isnot to be limited by any detail or details, except as defined by the following claims.

I claim:

1. In a structure of the class described, a feed pipe, a heater on said pipe, a tank on said pipe, means associated with said tank adapted to remove vapors therefrom at a predetermined limited rate, and a device associated with said tank adapted to produce a warning when the pressure in said tank exceeds a predetermined upper limit.

2. In a structure according to claim 1 wherein the tank is further provided with means adapted to withdraw liquids introduced into said tank through the first mentioned pipe.

3. A structure adapted to detect the presence of excessive quantities of water in an oil passed therethrough which comprises a tank, a pipe leading into said tank, a heater on said pipe adapted to preheat the liquid mixture conveyed thereinto through said pipe, means communicating with said tank adapted to remove the vapors therefrom at a predetermined constant and limited rate, means communicating with said tank 7 adapted to remove continuously the oil from said tank, and a device on said tank adapted to produce a warning when the pressure in said tank exceeds a predetermined upper limit.

4. In a structure according to claim 3 wherein the pipe leading into the tank is provided with means adapted to regulate the rate of flow of the liquid mixture into said tank.

5. A structure adapted to detect the presence of excessive quantities of water in an oil passed therethrough which comprises a tank, a pipe leading into said tank, a heater on said pipe adapted to preheat a liquid mixture conveyed thereinto through said pipe, regulating means on said pipe adapted to maintain a substantially uniform liquid level in said tank, a pipe communicating with substantially the upper portion of said tank, means on said pipe adapted to r move the vapors from said tank and through said pipe at a predetermined constant and limited rate, means communicating with said tank adapted to remove the oil continuously from said tank and a device on said tank adapted to produce a warning when the pressure in said tank exceeds a predetermined upper limit.

6. In a structure according to claim 5 wherein the last mentioned device produces an audible warning when the pressure in the tank exceeds the predetermined upper limit.

EDWARD G. RAGATZ. 

